1. Field of the Invention
This invention relates to an adjustable reclining lounge chair, and more particularly to such a chair in which the chair seat and back are supported for simultaneous stepless movement to an infinite number of locked positions between a fully upright and a fully reclined position to provide the desired position of comfort for the chair occupant.
2. The Prior Art
Reclining chairs of various types are well known and have been widely used for many years. One type of reclining chair which has met widespread commercial acceptance employs an articulated linkage mechanism interconnecting and supporting the seat and back on the stationary arm frame to produce complex movement of the seat and back upon application of force by an occupant's legs and/or arms, in combination with the occupant's weight, to produce the desired position change. Such mechanisms normally support the occupant in the selected position by the non-locking mechanical configuration of the articulated linkage which may be overcome by shifting the weight of or applying force by the occupant.
Another type of reclining chair well known in the industry employs a back pivoted to rigid side frames and having its bottom edge hinged to the back edge of a seat which, in turn, is supported for sliding or rolling movement adjacent its front edge. This type of chair structure is illustrated, for example, in U.S. Pat. No. 2,522,246 and Pat. No. 2,599,079, each of which discloses releasable means for locking the chair in the desired position. U.S. Pat. No. 2,522,246 includes a "shock absorber" type of motion restricter to permit a slower, controlled movement of the chair from one position to another.
U.S. Pat. No, 2,346,629 discloses a reclining chair including a back pivotally supported on rigid side frame members and extending downwardly therefrom to have its lower edge pivotally connected to the rear of a seat frame. The forward portion of the seat frame is supported by a pivoted link extending upward and connected to the rigid side frames so that the seat frame, back frame, rigid side frames and the pivoted link form, in effect, an articulated parallelogram support for the seat. Each joint of the parallelogram includes an adjustable frictione element to provide continuous frictional resistance against movement, which frictional resistance is overcome manually by a person occupying the chair. The friction joints are relied upon entirely to maintain the chair in its selected position of adjustment.
U.S. Pat. No. 2,611,421 discloses a reclining-style seat intended for use on an aircraft or the like, with the back being pivotally supported at each side to a rigid support post and having its bottom edge portion pivotally connected to the rear of the seat frame. The forward portion of the seat frame is supported by an elongated shaft extending through a guide sleeve, and latching means which is spring biased to the locked position may be overcome by a manually operated lever mechanism. The back frame and seat frame are connected in a manner to permit the back to be folded into overlying position above the seat for storage.
U.S. Pat. No. 4,607,833 discloses a reclining chair mechanism including a back frame pivotally mounted at each side to upwardly extending rigid arm support frame members and having its bottom edge hingedly connected to the rear of a seat frame. The seat frame has its forward edge pivotally connected at each side to a sliding friction block constrained within an upwardly inclined track or tube to permit forward and rearward movement of the chair seat and simultaneous elevation or lowering of the front seat upon pivotal movement of the chair back. Weight of the chair seat and of a person occupying the chair, acting on the friction blocks, resists reclining movement and to hold the chair in the selected reclined position.
U.S. Pat. No. 4,200,332 discloses an adjustable work or office chair including a linkage mechanism interconnecting the back and seat at the back of the chair, with the seat being connected at the front of the chair to the chair frame for limited pivotal movement about a horizontal axis. The linkage mechanism includes a combination mechanical and gas spring, with the gas spring including a control mechanism permitting the seat and back to be reclined about the horizontal support axis at the front of the chair and for limited rocking movement. The front of the chair seat is essentially stationary, with screw fasteners securing the front of the seat to the stationary frame shell.
While fluid cylinders, either alone or in combination with mechanical spring means, have been employed to control or assist in the reclining function of reclining seating units, the known structures employing such fluid cylinders have not been entirely satisfactory for use in a loungetype reclining chair. For example, in the known structures, the fluid cylinders generally have either operated only to control movement of the chair back while the seat portion remained essentially fixed or, due to the manner in which the back pivots are located with reference to the hinge connection between the seat and back, the back pivoting motion would push the occupant uncomfortably forward while only partially reclining the chair. In the case of Pat. No. 4,200,332, a gas spring is employed to permit rocking movement about a preselected reclining position for the chair back in a work station or desk chair and for this purpose appears to disclose a successful application of the gas spring although the structure would not adapt itself to incorporation in a lounge-type chair.